I'm 6 ft tall and use a 60cm axe. I only use it on snowy & icy slopes, and the 60 cm length seems about right for what I do. I don't limit my axe to winter use - it makes a great spring-summer-fall digging tool, bullet-proof tent stake, and for digging out chunks of hard snow for melting into water in high, If I had enough cash, I might even buy a shorter axe strictly for non-winter use.
Cheers.